1. Field of the Invention
The present invention relates to a video encoding apparatus for converting a digital video data signal into an analog video signal to be output to an image display device.
2. Description of the Related Art
Technological innovations in image display devices have been remarkable in recent years. Image display devices such as plasma TV's and LCD TV's are becoming popular which are compatible with the High Definition (HD) standard which defines a resolution of 1920×1080 or a standard conforming to the HD standard.
In this background, image contents compatible with the HD standard have also become popular. For example, Digital Versatile Discs (DVD) compatible with the next-generation Blu-Ray standard or the HD-DVD standard have been produced. These next-generation DVDs support high-definition HD images. As image contents such as movies are recorded in next-generation DVD media in the form of HD images and are distributed widely, copyright problems like unauthorized duplication might occur.
A next-generation digital interface standard called High Definition Multimedia Interface (HDMI) is established in association with the HD standard. HDMI allows HD images to be transmitted in a digital format, while also providing rigorous digital copyright protection.
Meanwhile, many image display devices with HD resolution capabilities are not provided with HDMI yet and are only provided with a D3 terminal, a D4 terminal or a conventional analog interface such as a component terminal. In this situation, electronic appliances such as DVD players and game devices for outputting an image are designed to interface with an image display device, using two interfaces, namely, HDMI, which is capable of transmitting a digital signal, and a conventional analog interface capable of transmitting an analog video signal.
It will be noted that copyright related problems such as unauthorized duplication are not likely to occur if image data is transmitted to an image display device in the form of a digital signal via HDMI. On the other hand, transmission of high-definition HD images via an analog interface may result in unauthorized duplication of high-quality image data because of poor protective function of the analog interface.